html,body{
    margin: 0;
    width: 100%;
    height: 100%;
    background-image: linear-gradient(to right, #fe6658,#0ca5c2);
}

.container{
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    .item{
        background-color: rgba(255,255,255,.3);
        color: #fff;
        width: 50px;
        line-height: 50px;
        height: 50px;
        border-radius: 50%;
        text-align: center;
        position: absolute;
        top: 0;
        left: 0;
        cursor: pointer;
        z-index: 0;
        visibility: hidden;
        &:hover{
            color: yellow;
        }
        &.main{
            position: relative;
            z-index: 10;
            visibility: visible;
            overflow: hidden;
            span{
                position: absolute;
                left: 50%;
                top: 50%;
                transform: translate(-50%, -50%);
                transition: all .3s;
                &.active-txt{
                    opacity: 0;
                    transform: translate(-50%, 0);
                }
            }
        }
    }
}